This application relates to a cleaning device for use in an image forming apparatus that employs electrophotographic technology, such as a printer, a copier or a facsimile machine. The application also relates to an image forming apparatus including the cleaning device.
A conventional image forming apparatus incorporates a cleaning device therein. The cleaning device removes residual toner that remains on a photosensitive drum after a toner image is transferred to a print medium. A cleaning device that has a cleaning blade made of rubber is well known. In this cleaning device, the cleaning blade mechanically scrapes residual toner from the photosensitive drum. Japanese Patent Laid-Open No. 4-172486 discloses one such cleaning device.
The cleaning device disclosed in the publication No. 4-172486 includes a cleaning blade, a plate spring and a blade-fixing bracket. The cleaning blade, which is made of rubber, is in contact with a photosensitive drum and extends in a longitudinal direction thereof. The plate spring supports the cleaning blade on its first surface and is attached to the blade-fixing bracket at its second surface, which is opposite to the first surface.
In the aforementioned cleaning device, however, the rigidity of the cleaning blade is liable to vary depending on the usage environment of the image forming apparatus in which the cleaning device is installed, which results in bending, or deformation, of the cleaning blade in a manner such that the cleaning blade departs from linearity in the longitudinal direction and such that the cleaning blade is no longer parallel to the axis of the drum. If the cleaning blade is so deformed, the pressure of the cleaning blade against the photosensitive drum varies, which causes residual toner that has a small average particle size to pass between the cleaning blade and the photosensitive drum. This will cause insufficient cleaning, resulting in loss of print quality.